Emit only one note per struct when multiple fields would trigger the same compiler note

[bruxisma]

Given the following code:

#[derive(Debug)]
pub struct Whatever {
  pub field0: (),
  field1: (),
  field2: (),
  field3: (),
  field4: (),
}

The current output is:

warning: field is never read: `field1`
  --> src\cmake\preset.rs:23:3
   |
23 |   field1: (),
   |   ^^^^^^^^^^
   |
note: `Whatever` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
  --> src\cmake\preset.rs:20:10
   |
20 | #[derive(Debug)]
   |          ^^^^^
   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: field is never read: `field2`
  --> src\cmake\preset.rs:24:3
   |
24 |   field2: (),
   |   ^^^^^^^^^^
   |
note: `Whatever` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
  --> src\cmake\preset.rs:20:10
   |
20 | #[derive(Debug)]
   |          ^^^^^
   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: field is never read: `field3`
  --> src\cmake\preset.rs:25:3
   |
25 |   field3: (),
   |   ^^^^^^^^^^
   |
note: `Whatever` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
  --> src\cmake\preset.rs:20:10
   |
20 | #[derive(Debug)]
   |          ^^^^^
   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: field is never read: `field4`
  --> src\cmake\preset.rs:26:3
   |
26 |   field4: (),
   |   ^^^^^^^^^^
   |
note: `Whatever` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
  --> src\cmake\preset.rs:20:10
   |
20 | #[derive(Debug)]
   |          ^^^^^
   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

Ideally the output should look like:

warning: field is never read: `field1`
  --> src\cmake\preset.rs:23:3
   |
23 |   field1: (),
   |   ^^^^^^^^^^
   |

warning: field is never read: `field2`
  --> src\cmake\preset.rs:24:3
   |
24 |   field2: (),
   |   ^^^^^^^^^^
   |

warning: field is never read: `field3`
  --> src\cmake\preset.rs:25:3
   |
25 |   field3: (),
   |   ^^^^^^^^^^
   |

warning: field is never read: `field4`
  --> src\cmake\preset.rs:26:3
   |
26 |   field4: (),
   |   ^^^^^^^^^^
   |
note: `Whatever` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
  --> src\cmake\preset.rs:20:10
   |
20 | #[derive(Debug)]
   |          ^^^^^
   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

Or something even more compact if possible. Without this, compiler output is almost double, and mostly unnecessary.

[dullbananas]

It should be even more compact, like this:

warning: `Whatever` has fields that are never read
  --> src\cmake\preset.rs:23:3
   |
23 |   field1: (),
   |   ^^^^^^^^^^
24 |   field2: (),
   |   ^^^^^^^^^^
25 |   field3: (),
   |   ^^^^^^^^^^
26 |   field4: (),
   |   ^^^^^^^^^^
   |
note: `Whatever` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
  --> src\cmake\preset.rs:20:10
   |
20 | #[derive(Debug)]
   |          ^^^^^
   = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)